Predicting Why, When and Where the metals fail

The experiment aims to reveal the microscopic physics of how metals break. It is well known that ductile failure takes place by nucleation, growth and coalescence of voids, yet the microscopic understanding of interaction between void evolution and the local structure is lacking. The deformation microstructure is a hierarchical organization with grains comprising subgrains of varying orientation and stress. Recently we have generalized 3DXRD for studying sub-µm sized subgrains. For its first application, we propose to map all subgrains in a relevant volume of a deformed Al polycrystal and correlate with a 3D movie of the void dynamics from tomography. This correlation will allow us to identify the origin of failure. Expected results will guide the theory with respect to how microstructural features affect failure. Specifically, these results will be compared to crystal plasticity simulations extended by a dilatational model of void growth and serve as a guide for model development.